江淮流域杂草稻叶绿体DNA的籼粳分化

 为了探明江淮流域杂草稻的细胞质来源,根据水稻叶绿体DNA ORF100（Open Reading Frame 100）序列在籼粳间存在69 bp差异的特征,设计了InDel标记cpDNA69。利用该标记对2个分别以籼稻和粳稻为母本的F2群体、22份栽培稻（Oryza sativa L.）、3份普通野生稻（O. rufipogon Griff.）进行了分析验证。PCR结果可以获得缺失和非缺失两种带型,缺失带型与以籼稻为母本的F2群体、10份籼稻材料完全对应;非缺失带型与以粳稻为母本的F2群体、11份粳稻材料完全对应,3份广西普通野生稻为非缺失带型,属粳型,1份以粳稻为母本的籼粳杂交材料为粳型。因此,cpDNA69可以用作叶绿体籼粳鉴定标记。利用该标记对22份杂草稻的叶绿体DNA鉴定的结果表明,7份早年发现的杂草稻,即江苏省连云港穭稻和安徽省怀远、来安、全椒、肥东的塘稻的叶绿体DNA为非缺失带型,属粳型,而近年来在江苏省扬中、高邮、灌云、洪泽、盐都、兴化、如皋等地直播稻田发现的15份红米杂草稻的叶绿体DNA为缺失带型,属籼型。这为进一步研究江淮流域杂草稻的来源提供了依据。     

四个丹东杂草稻的形态与微卫星标记分析研究

本研究采用19对籼粳特异性水稻微卫星标记,分析比较了4份丹东杂草稻（WS、WL、BS和BL）与标准籼粳对照品种之间的差异.同时应用程式指数法根据稃毛、酚反应、穗轴第1节间长度、抽穗时壳色、叶毛和谷粒长宽比等6项指标对杂草稻的籼粳属性进行分析.分子标记分析及形态特性分析结果表明,WL属粳型,另外三份杂草稻属于偏粳型.另外,发现丹东杂草稻和粳稻测验种的亲缘关系比东乡野生稻更近,表明杂草稻属于粳偏栽培型.由此推测丹东杂草稻可能是由古老栽培稻演变而来.试验结果对进一步了解研究杂草稻特性并在育种中利用其有利基因具有积极意义.     

江苏省杂草稻的传播与籼粳分化研究

21世纪初,杂草稻仅在江苏省局部区域发生,目前已扩大到全省,并对粳稻的高产和稳产造成严重威胁。为了掌握其快速发生机制,便于杂草稻的防除工作,需要进一步明确江苏省13市杂草稻是独立发生还是相互传播,以及江苏省杂草稻籼粳地理分布。采集了江苏省13个市58个样地的58个种群,总计205份的杂草稻样品。所有样品在南京农业大学江浦农场田间种植,并测量了38个形态学性状和6个程氏指数鉴别性状。欧氏距离聚类分析,表明江苏省13个市的杂草稻是相互混杂的。籼粳地理分布表明,江苏省杂草稻主要以籼型和偏籼型为主,籼型和偏籼型杂草稻在全部58个样点中都有分布,分别占样品总量的54.15%和42.40%;偏粳型和粳型仅分布于6个样点(淮安、苏州、盐城与扬州),分别占样品总量的2.93%和0.48%。此外,对比江苏省杂草稻的籼粳地理分布与江苏省地方品种的籼粳地理分布,未显示对应关系。籼粳比例和地理分布揭示了江苏省杂草稻主要为籼型,其中极少数为粳型杂草稻,粳型杂草稻的比例与杂草稻和栽培稻之间的自然基因漂移比例相近。     

亚洲栽培稻程氏指数与SSR标记分类的比较分析

 选取具有代表性的100份亚洲栽培稻品种,应用程氏指数和109个SSR分子标记对它们进行分类。结果表明,等位酶Ⅰ群（典型籼稻）和Ⅵ A群（温带粳稻）程氏指数和SSR标记亚结构特征均十分明显,拟合度较高（73.3%～100%）。Mantel检测揭示,程氏指数与SSR分子标记进行栽培稻分类存在明显的正相关,两种方法各个材料间遗传距离的相关达极显著水平（r＝0.466,P<0.01）。遗传结构和聚类分析表明,在籼粳亚种水平上,程氏指数和SSR标记分类结果趋于一致,但在亚种内亚结构分析中,程氏指数偏差较大,SSR标记具有更高的准确性。 同时, SSR分析表明混合型材料多存在于Ⅱ群和Ⅵ群内部。     

中国栽培稻及其近缘野生种叶绿体DNA的限制性片段长度多态性分析

 对中国现存的七省（区）的17份中国普通野生稻（其中广西普通野生稻6份，东乡野生稻5份，广东、湖南各2份，福建及云南景洪普通野生稻各1份）及28份栽培稻地方品种的叶绿体DNA进行了限制性内切酶酶切分析。28份中国栽培稻被分成三类，C1、C2和C3。其中C2叶绿体基因组类型仅有1份材料，为一个籼稻品种。两个主要类型C1和C3分别对应于粳型和籼型，说明中国栽培稻在叶绿体基因组存在籼、粳分化。17份中国普通野生稻的叶绿体DNA用同样3种内切酶酶切，共产生两种类型。它们分别与栽培稻中的C1和C3相同，其中C1类型占主要，为94.1％（16／17），具C3型叶绿体基因组的野生稻为１份广西材料。此外没有检测到新的类型。这说明在中国普通野生稻中也存在对应于栽培稻籼型和粳型两种不同的叶绿体基因组类型，而且是以对应于粳型的C1型叶绿体基因组类型材料为主。从大多数中国普通野生稻具有与粳型栽培稻相同的叶绿体基因组类型，可以推测粳稻起源于中国的可能性很大。     

基于植物学性状的吉林省杂草稻多样性研究

近年来随着直播技术和免耕方式的推广,杂草稻对水稻的危害越来越大,寻找有效的杂草稻防除措施己刻不容缓。本文对我国吉林省19份杂草稻植物学性状进行了调查,调查发现吉林省杂草稻抽穗天数和株高的变化范围均大于栽培稻,颖壳色多表现为秆黄色,赤褐色、黄色、黑褐色、紫黑色、灰黑色、黄褐色和银灰色;果皮色以红色果皮为主;大部分杂草稻有芒,芒色以秆黄和赤褐为主;易落粒;易倒伏。通过分层聚类将33份供试材料分为了5类。利用程氏指数法对19份杂草稻材料的籼粳属性进行分析,结果显示吉林杂草稻主要以粳型为主,少部分为偏粳型。     

籼粳亚种间核DNA特征性分子标记在美洲爪哇稻中的分布规律初步研究

对籼粳亚种间特征性SSR分子标记和ITS序列中特征性碱基在美洲爪哇稻中的分布特点进行了初步研究。结果表明,籼稻和粳稻特征性SSR分子标记在供试爪哇稻材料中都有分布,但不同爪哇稻品种所含籼稻或粳稻特征性分子标记的多少存在差异;通过对比ITS序列籼、粳特征性碱基,Lemont与籼稻一致,P002在4个位点与籼稻相同,2个位点与粳稻一致,另4个爪哇稻的ITS序列与粳稻完全一致。表明爪哇稻是介于籼、粳稻之间的中间类型,但不同爪哇稻品种偏籼或偏粳程度存在差异。     

两种生物型江都杂草稻不同栽播密度对水稻生长的影响及其与栽培稻的亲缘关系

 以两种生物型的江都杂草稻为材料,考查了杂草稻的生物学性状并对其进行了SSR分析, 旨在确定江都杂草稻的生物类型、遗传特性以及对栽培稻产量的影响。结果表明：杂草稻可分为两个生物型,一类是矮秆类型,包括JDWR A和JDWR C;一类是高秆类型,包括JDWR B。两种类型的杂草稻均属于籼型杂草稻。JDWR A与JDWR C亲缘关系较近,矮秆类型的杂草稻与高秆类型的杂草稻亲缘关系较远,而与杂交稻不育系亲本珍汕97A的亲缘关系较近。杂草稻与栽培稻的田间竞争实验表明,矮秆类型的杂草稻对栽培稻产量因子的影响更为严重。     

云南逃壳稻籼粳分类与形态性状的相关性研究

以程氏籼粳分类和俞履圻的变种变型分法对２０份云南光壳稻品种及籼粳测验种０２４２８、Ｄｕｌａｒ进行籼粳亚种、变种变型分类,并对其形态性状进行相关分析。结果表明,２０份云南光壳稻包括１３个变种６９个为型,以偏粳型品种占较高比例,籼粳分类品种中偏粳型品种的广亲和性较好。籼粳分类性状间及其与其他开矿性状尤其是花药长度、穗下节长和株高存在极显著的相关性,推断原始的云南光壳稻的籼粳分化取决于温度,并与纬度和海     

云南光壳稻籼粳分类与形态性状的相关性研究

以程氏籼粳分类和俞履圻的变种变型分法对20份云南光壳稻品种及籼粳测验种02428、Dular进行籼粳亚种、变种变型分类,并对其形态性状进行相关分析。结果表明,20份云南光壳稻包括13个变种69个变型,以偏粳型品种占较高比例,籼粳分类品种中偏粳型品种的广亲和性较好。籼粳分类性状间及其与其他形态性状尤其是花药长度、穗下节长和株高存在极显著的相关性,推断原始的云南光壳稻的籼粳分化取决于温度,并与纬度和海拔密切相关。     

我国常规稻主栽品种的遗传变异分析

 采用40个SSR标记,分析了329份我国近50年来常规稻主栽品种的遗传变异。结果显示,39个SSR标记具有多态性,在多态性位点共检测到223个等位基因,每个位点2～11个,平均57个;平均Nei基因多样性指数（He）为0632。籼粳亚种间的SSR变异差异明显,籼稻平均等位基因数（Na）和Nei基因多样性指数（Na = 54,He = 0440）均高于粳稻品种（Na = 44,He = 0397）。Nei遗传相似系数表明总体样本具有较小的遗传相似度（I = 0366）,而骨干亲本具有较高的遗传相似度（籼:I = 0590;粳:I = 0590）。这导致了籼粳亚种内较高的遗传一致性（籼:I = 0558;粳:I = 0600）。早、中、晚稻各类型遗传相似度差异明显,晚籼和早粳类型具有较高的遗传变异。籼粳稻品种尤其是粳稻的聚类结果显示出较强的季节型和地域特征。这些均提示育种家应选择更广泛的亲本源以拓宽选育品种的遗传基础。     

Genetic Diversity and Relationship of Weedy Rice in Taizhou City, Jiangsu Province, China

Microsatellite markers and morphological charactedstics were used to explore the genetic diversity and possible origin of weedy dce in Taizhou City, Jiangsu Province, China. Fifty-two weedy rice (Oryza sativa L.) accessions were compared with two wild rice, four hybdd rice and five cultivars using 22 simple sequence repeat (SSR) primer pairs. A total of 107 fragments were amplified, averaging 5.6 alleles per primer pair. The polymorphic index content (PIC) values ranged from 0.3077 to 0.7951, averaging at 0.5870. The average genetic distance of all samples ranged from 0.02 to 0.46 with an average of 0.262. The genetic distance among Taizhou weedy rice ranged from 0.03 to 0.44 with an average of 0.224. Cluster analysis showed that all the weedy rice accessions from Taizhou City were indica, and could be subdivided into different genotypes. The majority (86%) of weedy rice was most closely related to hybrid rice. The Taizhou weedy dce accessions were morphologically similar, but still could be delineated into indica or japonica group by some morphological traits. it is suggested that the levels of genetic and morphological diversities of weedy rice in Taizhou City are low and these weedy rice plants originated from the segregating progenies of hybrid rice that had naturally introgressed with cultivated rice.     

Genetic Diversity and Allelic Frequency of Selected Thai and Exotic Rice Germplasm Using SSR Markers

A collection of 167 Thai and exotic rice accessions was subjected for evaluation of genetic diversity and assessment of relationship by simple sequence repeat(SSR) markers. Among a total of 49 SSR markers, 13 markers distributing over 12 rice chromosomes showed clear polymorphic band patterns, and they were selected for genetic assessment. A total of 110 alleles were detected with an average of 8.46 alleles per locus. The averages of gene diversity, heterozygosity and polymorphic information content were 0.59, 0.02 and 0.56, respectively. The unweighted-pair group method with arithmetic averages(UPGMA) clustering analysis was performed for genetic distance, and phylogenetic tree was constructed. The result showed that this rice collection was divided into two major groups, classified as japonica and indica subspecies. Within the japonica group, temperate japonica and tropical japonica subgroups can be clearly separated. Three-dimensional principal component analysis projection and model-based population structure analysis showed consistent clustering results with two major groups of UPGMA analysis, supporting the classification of japonica and indica subspecies. The indica allelic frequency was also investigated to provide an indicative guide for breeders to overcome the practical problems on sterility of inter-subspecies hybrid offspring. This rice collection and information obtained in this study will be useful for rice breeding programs.     

利用微卫星标记分析浙江省近年来主要水稻品种的遗传多样性

 利用12个DNA微卫星标记分析了浙江省近年来主要的44个常规水稻品种和54个杂交水稻组合,共检测到等位基因68个,每个标记2~10个;带型数共127种,每个标记3~18种;平均多态性频率0.752,变幅为0.567~0905。常规品种和杂交组合均表现为亚种间遗传差异明显、亚种内遗传差异较小,籼型遗传多样性高于粳型。平均遗传相似系数,常规品种籼型为0.672,粳型为0.711,籼粳间为0.103,杂交组合籼型为0.636,粳型为0.669,籼粳间为0.343。聚类分析显示,以遗传相似系数0.618为阈值将常规品种分成6类,以0.601为阈值将杂交组合分成7类,且多数同类型品种或组合聚为同一类。     

Genetic Structure and Indica/Japonica Component Changes in Major Inbred Rice Varieties in China

We used 39 SSR markers to analyze the genetic structure of 304 major Chinese inbred rice varieties, and to compare changes in the indica or japonica components in these varieties that have been widely cultivated from the 1950s to the 1990s in China. The genetic structure analysis showed that these rice varieties were distinctly divided into two populations, indica and japonica. The sub-structure of indica varieties was more complex than that of japonica ones. Among the various lines, late-season indica and early season japonica varieties had simpler genetic backgrounds. The seasonal ecotypes were not quite consistent with the subtypes of genetic structure. Twelve SSR loci with specific differentiation between indica and japonica were used to calculate the indica/japonica components. The differences in indica/japonica components among the five decades were not significant, except for late-season indica varieties in the 1990s, which had a significantly higher japonica component. These results will help to understand the genetic structure of the major Chinese inbred rice varieties and will be useful for indica-japonica hybrid breeding in China.     

Comparison of Cheng’s Index-and SSR Marker-based Classification of Asian Cultivated Rice

A total of 100 cultivated rice accessions,with a clear isozyme-based classification,were analyzed based on Cheng’s index and simple sequence repeat (SSR) marker.The results showed that the isozyme-based classification was in high accordance with that based on Cheng’s index and SSR markers.Mantel-test revealed that the Euclidean distance of Cheng’s index was significantly correlated with Nei’s unbiased genetic distance of SSR markers (r=0.466,P ≤ 0.01).According to the model-based group and cluster analysis,the Cheng’s index-and SSR-based classification coincided with each other,with the goodness of fit of 82.1% and 84.7% in indica,97.4% and 95.1% in japonica,respectively,showing higher accordance than that within subspecies.Therefore,Cheng’s index could be used to classify subspecies,while SSR marker could be more efficient to analyze the subgroups within subspecies.     

我国水稻主栽品种SSR多样性的比较分析

采用40个SSR标记,比较分析了151份20世纪50年代(78份）和近10年（73份）我国常规稻主栽品种的遗传差异,发现有39个标记具有多态性,多态性位点共检测到213个等位基因,每个位点2～11个,平均5.5个;平均Nei基因多样性指数(He)为0.649,范围在0.309（RM174）～0.869（RM418）。籼粳亚种间SSR多样性差异明显,籼稻平均等位基因数（Na）和Nei基因多样性指数（Na = 4.4,He = 0.458）均高于粳稻品种（Na = 4.0,He = 0.395）。比较了78份20世纪50年代与73份近10年水稻主栽品种的遗传多样性,籼、粳亚种表现出相近的变化趋势,即Nei多样性指数和等位基因数20世纪50年代主栽品种高于近10年的。虽然Nei基因多样性指数的变化并不显著（籼稻：z= 1.471,P=0.141;粳稻：z= 1.932,P=0.053）,但等位基因数目的变化达到显著水平（籼稻：z= 2.677,P=0.007;粳稻：z= 3.441,P=0.001）。分子方差分析(AMOVA)表明,遗传变异绝大部分存在于两时期内,尽管时期间平均贡献的遗传变异仅占1.9％,但仍然达到5％的显著水平;籼、粳亚种两时期间平均贡献的遗传变异高于整个分析样本,分别为5.0％和8.2％;籼、粳亚种不同位点的遗传分化程度也各不相同,籼稻和粳稻品种分别有13个（占33.3％）和11个（占28.2％）SSR位点的等位基因在两时期间差异显著,而其余位点的遗传变异则是因时期内品种间的差异引起的。研究表明近10年我国常规稻主栽品种丢失了一部分等位基因,水稻育种仍应加强更广泛的种质亲本的选择。